Balloon Repair Station

Guide to Inspecting Burners

Guide to Inspecting Burners Last update 26.01.2015

This guide is designed to assist with the general inspection of hot air balloon burners and highlights a number of areas where special care and attention needs to be taken. In all cases the Manufacturers’ latest Maintenance Manual and Inspection Schedule must be used when inspecting them and must be adhered to. Airworthiness Directives and Manufacturers’ Service Bulletins must be checked prior to inspection and the burners checked to ensure compliance.

There are innumerable combinations and permutations of burners, valves, hoses and fittings so what we will do here is go down the route of looking at the burner as a whole then concentrate on the fittings. Fortunately this really only applies to the older burners some of which have scuttled off to the collectors shelves or museums. Having said that they do creep up unexpectedly but in the main we’ll go from the Cameron Mk4 and Colt C2 onwards and Ultramagic Mk21. Lindstrand burners have changed little apart from cosmetically since their inception. In the case of hopper burners we’ll do that in a separate section. Where valves are the same we’ll simply repeat the information rather than refer you back to another burner that used it.

We’ll further break up the Guide by dividing it into basic rules, hints and tips for general testing, burner frames, gimbal systems and hoses. After that lot we’ll concentrate on individual burners by manufacturer, in alphabetical order lest you think we are favouring one against the other.

The order of the inspection isn’t set in stone but more or less what we do. In truth we check the hoses first then the burner but occasionally it’s the other way round. Just that if the hoses are knackered it makes you a tad more cautious! Whatever, everything is checked first without propane being introduced. Once we are happy then it gets hooked up and pressurised.

Where field adjustment is deemed possible it will be noted but you are not going to find any repair methods described here. If repair or adjustment is required then you must refer to the appropriate Manufacturers’ Maintenance Manual. Where there is a degree of permissible damage, or a grey area where an advisory may be an option, then it will be discussed.

Basic Rules
The following test is split into two distinct parts. A general procedure and then things to watch for on, or tests specific to, a particular burner. Read through the general Guide then refer to the specific burner you are testing for further information or clarification on the possible cause of the problem.

It doesn’t really make much difference whether you choose to inspect a burner ‘rigged up’ to the basket or stand alone. What is import is that you are able to see the burner and all aspects of its operation. This isn’t always possible with the burner rigged, especially in the case of smaller and more common burners. In the case of triple and quad burners there often isn’t an option and they come rigged. Thankfully you will be able to stand on the basket to get a better or closer look something not always practical on a 77. We generally test smaller burners as a stand alone assembly on the ground so that is what we will assume here.

If you find a fault always try and look beyond it to find the cause. It may simply be that the valve leaks because its never been lubricated or is simply past its sell-by date and knackered. On the other hand a bent H-bracket on a double burner may be caused by the way it is lobbed unceremoniously into the basket and everything dumped on top of it equally as much as if the balloon has turning vents and the pilot always lands the same way round and holds onto the crosstube during landings. You need to find out if you can what the reason for the failure is and if its something that can be prevented with a bit of advice you should give it.

Keep notes as you go. If you’ve advised the gentle-person that the hoses will need changing next year or it would be a good idea to fit some new corner rubbers then write it down.

The biggest mistake made when inspecting burners is that the inspector treats the inspection as a pre-flight check ensuring everything works. We are not looking for what works but looking for what is awry and what doesn’t work properly. Remember you are not under pressure to fly! You are inspecting not doing a pre-flight check.

Golden Rule 1
Just because the owner tells you it’s a smashing burner and has never let them down and still has the original ‘O’ rings fitted that just might not be the complete truth. In the case of modern burners owners often have no idea how they should be if they ae working correctly never mind that they actually have a fault. I could tell you loads of stories where we have found something quite seriously wrong with a burner and the owner has in innocence said that hadn’t realised that was a fault or that anything was wrong, until that is, you mend it!

Recording the numbers - Mucho important
We always get this out the way first. It makes the rest of the inspection a lot easier as you don’t have to break routine to note that the follicle toggle is knadgered on…. now which one is it? Almost all the Cameron burners use individual numbers in the centre on top of the coil. T&C C2 and C3 and Magnum doubles have them engraved on the one of the brackets linking them together the singles have them on one of the coil uprights. Lindstrands are on the top of the connecting block between the cans or on a coil upright if it’s a single. Ultramagic individually numbers the burners on a coil upright, later ones have a nice little plate on the burner block. T&C (Cameron) Stratus are complete arses with the numbers on the top of the block at the bottom of the can sort of where the pipe to gauge goes. You will grow to hate that design feature. Sky burners are either on the burner block. Siroccos have no idea what their number is as they have two, more later. Hoppers to have there own bizarre rules when it comes to numbering and that will be discussed under the respective burner.

General Guide to Inspecting Burners

Appearance - General Condition
Numero Uno get everybody back and open the blast valves to make sure the pilot cleared the lines the last time they flew. Of course they always do! If you’ve got the burner on the deck to inspect it the bloke standing in front of it will be the pilot. Always is, no idea why. If it’s a normal person basket you may find it easier to lay the basket down at this stage to check things.

This is have a general good look at the burner time. Does it look like someone has dropped a cylinder on it? Is the burner frame square? Do the coils look twisted or distorted. Is it clean or covered in cobwebs and bird droppings? All these things will give you a heads up about its general condition, how the owner cares for it and clues of what may be amiss with it. If it has cobwebs and strange all over it for example it may not have been used for ages. Seals may be dry and valves stick the hoses may be split or stiff and brittle. Use is good, leaving in a damp trailer for a year is decidedly not. Don’t be fooled by appearances though. Just because a burner is shining like a diamond doesn’t mean its all well. Although an owner may well lavish a lot of care and attention on their kit it doesn’t necessarily mean there are no problems with it. Similarily a regularily used, high hours, quad burner can resemble an oil refinery but it may be well cared for and being in regular use it may well be perfectly OK.

Be objective with the coils. Quite why anyone would ever think it would be a good idea to make coils that expand and contract, quite dramtically, square has always been a puzzle. We do know the reason and it will be in my book but for now just be amazed and assume that it is to make the expansion more exciting and noisy. If coils are twisted or distorted how distorted are they? The coils themselves should be retained, or at least restrained, in their guide pins on the uprights and not free-floating in space. Looking down the top of the top the coils and their top feeds (if fitted) should not obscure the jet ring or whisper jet. What you have to ask yourself is this. Are the coils being abraded by their guide pins or loose enough to move sufficiently to induce abrasion and where they can move is there any sign of rubbing or abrasion. Its fair enough to say that they have probably been like that for years but so is woodworm in York Minister. Sooner or later a little devil will take that all important bite. If the coils are distorted but deemed OK note it in the logbook.

Where the feed runs into the top of the coils make sure that they do not cross above the whisper valve. Believe it or not we have seen this and it can only be the result of the coils being reassembled incorrectly.

Look at inside of the burner and note if there is any localised discolouration or sooting. This can be a good pointer to leaks.

Have a good look around and look to see everything is where it should be. Get a feel for it, does it all feel nice and tight? Make sure all the nuts and bolts and jets are in place not loose and in one bit. Make sure slurpers are in place and not loose.

Open and close all the valves. Make sure that they operate through their range and, in the case of toggles, snap shut on release. Make sure over-centre toggles will go over centre and squeeze-type levers aren’t fouling on the slots in the burner cross tubes. Check that they are tight and any lock nuts, wire or pins are in place.

Check the gauges making sure the glass isn’t broken, cracked or missing and that they read zero. If they are sitting just above zero give then a flick and see if that zeros them. Make sure that the gauges are sitting as they should and not loose in the can or burner block.

Igniters
Flick the igniters and check that they are sparking and that the spark might actually be capable of setting fire to propane. The igniter when depressed should click smoothly and generate a spark consistently and, yes, the button should pop back out without a protracted onset of teasing, twisting and random bashing. Remember though that condensation can often short out the igniter, its lead or electrode so if you don’t get a spark don’t panic, you can try again once you’ve done the actual burner test. Quite often igniters work only once the things been warmed up.

Grot on the pilot pot or end of the electrode is the most common reason that sparks fail or are intermittent. A quick clean with a bit of Emery the Eighth usually does the trick but be very careful not to bend the electrode if its surrounded by a ceramic insulator otherwise there is a risk of breaking it.

If no spark is apparent it may also be down to the gap between the electrode and can or a hairline crack in the electrode. Tiny cracks can sometimes be spotted as back sooted lines on the ceramic. Believe it or not a decent nail varnish can sometimes resolve the problem.

Often its more obvious so check ceramic insulators for cracks. Sometimes the ceramics can be broken in two yet the igniter still function. Advise the owner accordingly. Make sure any leads are well out of the way of the hot bits and not burnt or cracked. This is often the cause of intermittent sparking.

Hoses and connectors
Steady now, we will be firing the thing up but not quite yet. No need to rush, the pub isn’t open yet. If the burner is all rigged up then get the fellow to take all the leg leathers off so you can see the hoses. Now here’s alittle story to make you chuckle. We inspected a balloon once belonging to a legend in ballooning and failed a liquid hose. He was mortified being from up north as he knew the cost of such things. “But that was only fitted a few years ago”, he pleaded. “No it wasn’t”, we explained, “it was fitted around 1989”. “How do you know that?” he enquired realising he may be mistaken. ‘Well”, we said pointing to the hose,”Its got 1989 printed on the hose.”

Hoses tend to last between 8-10 years and most have a date on them somewhere. The older the hose the harder you need look. Although we would never encourage lifing 10 years is a good whack for hose. Yes, we know vapour hoses only carry vapour at a low pressure their integrity is just as critical and the same criteria apply. Now grasping a hose at the burner end commence checking.

First off check the swaging, the pressing over the fitting, isn’t damaged or corroded.

Next off bend the ends of the hose back on themselves at the burner and check for cracks or splitting. Do the same thing down its length and repeat at the connector end. There should be no bulging, cuts, abrasions (rubbing from control lines is the most common), kinks and dents (from being crushed under a cylinder for example), cracking (visible ageing) and no internal steel braiding should be visible and the hose must still be flexible. Now as the hoses age they harden and will start to develop surface crazing. If the hose is less than ten years old (as a guide) still nice and flexible and its only very light an advisory may be OK. If its rampant down the entire length, the cracks can be opened appreciably when the hose is bent over and it is clearly a few years old then it’s a failure. If you choose to make it advisory then make a note of it in the logbook when you release it back to service.

Some manufacturers delight in putting coloured shrink wrap on the hose ends especially on triples and quads. If you have ahlf a suspision that cracking or splitting may be taking place under it then its got to come off. Hoses on Ride balloons where the burners are kept rigged account for the majority of failures through cracking, splitting or abrasion. Some operators fit hose or wrap tape round the hose to try and prevent chaffing but bear in mind it can be that chaffing has already taken place so have it ‘orf and check.

Now you may well need to be a bit of a detective here. In the past there was a really bad practice of people getting hoses shortened if the end started to crack or split. Fortunately, throughout industry, this practice is now banned and I would think that any that had been so treated have been picked up and outed following the publicity given to the subject in past Inspector Infos. It doesn’t mean yu shouldn’t check though. If the swagings on each end are different or one looks very new and the other doesn’t you need to ask the question or just fail them.

Check the hose is to the correct specification. It should be SAE100 RIAT and be the correct diameter for the burner it is fitted to. Almost all the Cameron, T&C and Lindstrand burners use 3/8” internal diameter hoses. T&C Stratus burners sometimes use ½” internal diameter hoses but must have ½” hoses if they have crossover valves fitted. These are almost exclusively on the Stratos triple and quad burners. Ultamagic use 5/16” but you occasionally come across 3/8”.

Hoses must be pin-pricked down their entire length to prevent swelling following internal leaks.

Check that the correct thread is used for the correct fitting on the end and at the burner itself and onto the connector. It isn’t unknown for someone to try and muller a ¼” NPT vapour fitting into a ¼” BSP. Make sure that if a new hose has been fitted that it hasn’t been cross threaded, overtightened causing a crack in the burner block in the case of a tapered thread (NPT) or the Dowty seal has been left out or fitted using PTFE tape in the case of BSP (parallel) thread.

Check the Connector. If it’s a Tema are the seals present and undamaged? Is the fitting true in form and undamaged, does the locking ring appear to function, are the locking balls all in place and is the body free from any cracks? If it is a Rego are the threads all Ok, no crushing visible and on both types is the self seal nipple free. Use a popper to check. Now, if you forgot to vent the lines a tenner says you’ve got a face full of propane.

Repeat the process for all the hoses. Once that’s all done we are going to take a look at the burner proper and connect it up.

If you are in any doubt ever about the condition of a hose fail it. If you find something unusual, like an unexplained split or bulge in a newish hose then fail it and contact the manufacturer getting as much information off the hose as you can. If the hose has become stiff and its clearly getting on in years then its time for a change.

Burner Frames
Whether it’s a humble one man basket balloon or mighty compartmented passenger ride jobbie the outer burner frame is the load bearing part of any balloon. Not only does it transpose the load through the flying wires to the basket but it does so at angles various so any damage to the welds, cracks or distortion must be taken very seriously. Generally across the board repairs to burner frames have to be authorised. If a repair has been made to the frame and there is no entry in the logbook then you must satisfy yourself that it has been carried out in the correct manner. If the owner is unable to provide suitable evidence then the burner frame should be failed and referred, if applicable, to the manufacturer.

Look closely at the shape of the burner frame in both planes. If its more than slightly out of square or it is twisted through the horizontal plane then there is every chance that there may be damage to the welds or tubing itself.

Check the tubing on the frame. It shouldn’t be crushed or collapsed if its gone out of true. If it has then the integrity of the tubing has been compromised. Bracketry shouldn’t be impacted into the frame nor should be pulling out. Where frames have become distorted and have distortion in the frame attempting to pull them straight is not an option. This will only further weaken the tubing.

Look closely at each and every weld including in-between the brackets that the karabiners attach to. Check that there are no cracks eminating out from them. These often show up as a fine dark line. Where corner braces are fitted check them as well. In the case of burner frames fitted with lugs for attaching the Quick Release to make sure that if they have become bent no distortion has been inflicted on the the burner frame tubing. Look very closely at the join between between the weld and the tube. This is often where cracks develop. You will need a decent (x10) magnifying glass or your finger nail to initially confirm a crack. Specialist dyes can be useful in confirming hairline cracks. Don’t forget to look on the top and underneath the frame. One of the most common places to find cracks is at ends of the crossbar of centre-gimbal frames and on the hoops where they attach to the crossbar on triple and quad burners. On eight pole systems the most common place for cracks is between the karabiner brackets and the underside of the inner frame where the sockets attach.

Pole sockets, especially on the larger eight pole Ride balloon frames can be subjected to enormous stresses and strains during windy inflations so make doubly sure that there are no cracks where they attach to the frame and that they are not split.

The condition of the wibbly wobbly pole sockets on the Cameron frames are not part of the inspection however if the rubbers are missing then it advisable to replace them. The old rubber bushes have been replaced by nylon ones which soon become wibbly wobbly but won’t fly out at the touch of a gust of wind. There is an anomaly in that although Cameron balloons specify these are not an inspection point they do have a bit concerning the length of free play in burner support poles and if the rubbers are missing and the bolts that connect them to the burner frame are bent this will be exceeded. If the bolts are bent they will need replacing.

On older, as in ancient, burner support poles corner shackles are fitted to the frame. The shackles must be free of distortion or corrosion, and the shackle pin must be fitted with a lock nut. The corresponding clip on the support pole must work.

Check the basket cable brackets where the karabiner goes through. Is the karabiner free to swivel in it? Is there extreme wear to the hole such that the original drilling has opened up and are the brackets reasonably square to the frame tubing.

Now a quick word on the poles themselves. They should be in one piece not battered to death where they have been put under the basket to aid rolling it into the trailer. Cracks and splits equal failure. In the case of poles with turned ends the turned portion should run reasonably in line with the rest of the pole not be at a jaunty angle. If the angle is acute the next time round it is going to break. Of course this isn’t the end of the world as we didn’t have burner pole in the beginning but a shattering burner pole, I can tell you from experience, has a lot of gutty and could give you a nasty smack in the head! They should be reasonably straight. It isn’t true that if you put them in a hot bath they will naturally straighten out. Poles should fit into the sockets reasonably easily. Contrary to popular belief the nylon poles will absorb moisture and swell.If they are seriously tight then there is a risk, especially in fixed sockets that they could split them during a windy inflation and also damage the basket sockets. It is not at all unusual to find splits in both basket and burner pole sockets. Turning the end down slightly will help. A bit of decent wax and a good polish may help. Lubricating them with WD40 will not.

If there is an inner frame the same criteria apply. The most common area of failure is around the drillings that take the swivel bolts and the inner frame on triple and quads being twisted which tend to throw the burners out of line.

Gimbals

There are basically two types gimbal (not counting the Bonanno/Ultramagic Tekno single which has a swivel fitting). These are the frames that have a double set of swivels along with an inner and outer frame and the centre gimballed type.

Inner and Outer frame type
The gimbals on these are simply bolts, mostly shouldered, that run through spacers and friction washers. Now some owners will tell you they like their burner to be loose but truth is that they probably haven’t bothered to tighten the nuts and bolts up. It isn’t unusual to find a lock nut missing or the nuts being finger tight. Quite often the friction washer has broken up or at some time has been removed and then adjusted up without it. Early friction washers have now been replaced by nylon ones which last reasonably well. Whatever the pilot claims there should be some resistance to movement.

Obviously then the easiest thing to do if the burner isn’t rigged is to sit the coils top down on a mat and see how loose the affair is. You should be able to move the inner and outer frame and the burner to inner frame in all directions with a tad of friction. The lot shouldn’t rattle about or be loose.

Even if it moves with friction check that the nuts are not loose on the bolt especially the outer ones. On a single or double burner there are four swivels and it doesn’t take much to realise that friction can be achieved with only a couple of bolts being tight! On the lager triple and quad burners with swivel frames there can be three swivel bolts on the inner frame depending on the style of the inner frame. Check them all. There should, in the case of almost all the Cameron, T&C and Lindstrand burners, be a bolt with nut and locknut. In some cases, mainly T&C, there is also a split pin fitted.

The easiest way to check is to grasp the outer frame each side of swivel and try pressing the inner frame with your thumb. It shouldn’t move up or down. If you are not gifted with stubby thumbs then try and move the inner frame against the outer at the swivel.

Sometimes the burner rattles about yet the swivels are fine. In this case the movement is generally in the brackets where they attach to the burner can.

Quite a common find is an incorrect gimbal bolt has been fitted or a nyloc fitted in place of the nut and locknut usually an ‘in field’ repair to get into the air! All the nuts, bolts and split pins should be stainless steel.

Some burners are fitted with stops or straps to prevent the burner turning turtle. They must be in place and secure. In the case of restraint cables these must be undamaged. Move the burner throughout ts entire range and ensure any stops fitted function as they should and don’t catch or prevent the burner being returned to its normal operating position.

Centre-gimbal frames
Centre-gimballed frames have an outer frame with a cross tube that supports, via a block the burner. On larger baskets there may be two crosstubes running front to back of the frame supporting the tube carrying the block.

There should be no play in the burner with regards to the swivel block in either plane and there should be sufficient friction in the movement to ensure free movement of the burner but not allow it to flop about. Excessive play can be down to adjustment, worn or missing spring washers and friction pad in the block, a worn block or missing adjusting or securing bolts. Exceedingly stiff operation or ‘grating’ during movement can be down to no lubrication of the block.

If stops are fitted to the block or crosstube then they must be in place and function correctly. The burner should be free to move throughout its entire range without sticking.

To test for play in smaller burners then the it should be turned coils down on a mat and the frame and burners checked for play through the block.

On larger triple and quad burners try moving the burner up and down against the swivel block ensuring that there is no play in the block.

The burners are supported in the block by a swivel bracket usually ‘H-shaped’. Check the alignment of the burner cans. They should be inline with each other and the crossbar of the ‘H-bracket’.

Check the ‘H-bracket’ for cracks to the welds or distortion.

Check to make sure the bolts attaching the cans to the H-bracket are all in place and tight.

Depending on the burner type there may be a tube linking the burners which doubles (in some cases) as the carrier for the blast valves. If the H-bracket is badly bent then damage can be caused to this bar and impede the operation of the blast valves.

Adjustable height burners
There are a variety of adjustable height burners in circulation. Check the function and condition of adjustable height system by trying to adjust it obviously. Make sure thst there the whole caboush works as it should and all the bits are there. Make sure there is no play in the system outside of its design criteria and that there is no play in the inner and outer frames as described in that section. If a damper is fitted then check it for any sign of leakage. Be careful some of these, especially the Cameron ones, can have your finger off just handling them. Best thing to do is get the owner to demonstrate it!

Live testing - The No-Flame test
Now that’s all the prodding and poking looking and wriggling out of the way. Next thing to do is connect it up to a cylinder and test it out.

This next bit may well come as a surprise to some but we are now going to run neat propane through the burner without the pilot light lit. This is the best way to find leaks, even very small ones will show up. If you think this an odd thing to do here is a cautionary tale. We’d had someone down to go through inspection procedures the day before this incident. The victim was asked to carry out an inspection on a burner and he did so, in fairness, in accordance with a pre-flight check, lighting the pilot as soon as he was sure that the neither the hoses or the valves weren’t leaking. “Whoa up”, we said, “This is an inspection not a test”, and proceeded to explain about running raw propane through the system first. A few days later John was perched on the side of a big ride basket on the trailer and about to test the Lindstrand quad burners. He livened up the system and after the normal checks opened the blast valve and commenced dispersing propane through the burners. As a result the biggest cloud of propane shot out the side of the can. We traced the leak to the seals under the coil post. Had the pilot light been lit then it shudders to think what would have happened to John. Couple of words of caution though. When you do this get the pilot out of the way and don’t have a roll-up in your mouth. If the burners are rigged remember propane is heavier than air so watch you don’t do it for so long as it starts to either drip or fall back into the basket. It will take a few moments to dissipate.

First thing to do is find a cylinder with at least 35% of fuel in it and a decent but not necessarily massive pressure, it must be above the recommended minimum.

We do test smaller burners on the deck but big ride balloon burners are usually rigged. If they are rigged up you must ensure that you can look and see how they are working so on smaller baskets that standing on would be dodgy be prepared to tip the basket and burners over into the inflation position to get a better view of proceedings.

Make sure that the hoses run out from the burner at around 45º and do not cross in front of you nor could get in the way lest you have to beat a hasty retreat. Make sure a fire extinguisher is close by.

When attaching the connectors to the cylinders note how freely they go on. A squirt of WD40 will help. Not many owners lubricate their connectors despite swearing that they do so we just lubricate O-rings before testing.

Rego connectors should screw on quite easily and go fully up without the resort to pliers or two hands! If it doesn’t have a close look at the threads and make sure there is no flattening of the fitting. It isn’t unusual for this often caused by a cylinder being dropped into the basket onto the fitting. You may still be able to scrwit on but it will be extremely tight. You don’t want that if you are changing cylinders in a hurry. Tema fittings should push fully down and the anchor ring click into place without assistance. Check that the locking ring actually locks and unlocks correctly.

Same thing applies to the vapour hoses. Make sure they pop in nice and sweetly and can’t be pulled out. Again a squirt of WD will help.

Get the pilot to move away from in front of the burners (again) and stand somewhere less hazardous. You could suggest he turns the cylinder valves on and off for you, that should keep him out of trouble!

Make sure everything is turned off. Liven up one side (vapour as well if applicable). Listen for leaks of valves that haven’t shut properly. Often happens on Cameron adjustable whisper valves. If vast clouds of vapour eminate from the burner then you are going to have mend the leak or identify your options before continuing.

Spray some leak detector onto the hose connector(s), where the hose goes into the block or pilot assembly and around the ends of the swaging. Give it a minute to check for bubbles. Spray connections to any valve or gauge that operates before the main valve. Again wait a moment and check for bubbles.

Spray detector around the bases and stems of the valves and around the main feed to the coil not forgetting the pilot light, whisper valve and any pipework.

Open the pilot light valve and listen for a flow and check for leaks with leak detector. Turn it off and listen again to make sure it has closed. Adjustable pilot valves do occasionally continue running.

Open the blast valve and check the main feed to the coil connection for bubbles. It will freeze quite quickly so you’ll have to be sharp about it. Shut the valve and re-open it until you get liquid out of the jets. If there are any problems with connectors or loose jets you will see them as dark patches around the offending item. As the coils start to freeze any leaks as a result of abrasion small cracks or faulty welds will show up in a similar way. Shut the valve and listen to make sure it has closed.

Repeat on the whisper valve. If you can still hear even a slight rustle of propane (especially in toggle valves) then it is likely that the main seal in the bottom of the valve is damaged or worn. On lever operated whisper valves make sure there is no leak of propane usually indicated by a very fine mist of propane or freezing around the stem under the lever itself. The leak detector test should show it up but sometimes the propane causes freezing so quickly that it masks the leak.

In the case of foil-type burners running liquid through them will really show up areas that are blocked or distorted that lead to the poor flame patterns.

If you are checking a double burner (or any with crossfeeds) then you need to check the pipework and the valves in the same way.

Live Test - Fame (whoops) Flames at Last
When that is all done, the propane has drifted off and the burner has thawed out a bit you can light up the pilot. Remember ‘Lead with liquid, light last’. If it’s a vapour fed pilot light turn off the liquid valve before lighting the pilot just as you would in a standard pre-flight burner test. Now you may find a bit of a small fire develops in the burner. This is only propane frozen in the water burning off. Give the blast valve a few quick squirts to warm everything up and get rid of the frozen water. Beware on the foil-type burners as you will get an impressive plume rather than flame the first few times, especially if you don’t allow a bit of time for the jet ring to thaw out.

If the igniter doesn’t work or there isn’t one fitted then try and light the pilot manually. After you’ve warmed the burner up turn it off and try again. It may well work. Likewise after pumping neat unburnt liquid propane through it is often the case that the pilot won’t light straighaway but once its warmed up all should be well. If you can’t get the pilot to run you have a couple of choices. You can use an outside source, we use a plumber’s blow torch but a striker or matches will do, as a pilot or stop the inspection and repair the igniter before continuing. Breaking a routine or inspection is in my opinion unwise.

Once it appears all is warmed up then you can give it some gutty. Open the main valve fully and allow the burner to run for at least 5 seconds looking into the bottom of the can checking for random flames. These can be generated by loose or damaged jets, leaks from the coil to block (valve) connection or possibly the feed to the gauges. Loose crossover feeds are another possibly. Close the valve and make sure it shuts off. Next repeat the exercise, turning the valve through about 90º if it’s a toggle-type, and watch the coils to make sure that random flames are not shooting out of the coils (some burners do this as a design feature) and that the flame is not striking a distorted or twisted coil. Try and identify the problem. Random flames probably harken back to leaks around loose jets spotted earlier. Do it again (90º turn for toggles) and watch the flame pattern as it escapes the top of the coils once more looking for any random flame or strange flame patterns. If there are any it may be something as simple as a slurper being too far across the slurper jet or it could be a crack or leak in a weld or top coil. Now, last but not least, do another 90º turn and watch the flame pattern clear of the coils to ensure it is the right shape and colour. Throughout this test when you close the valve the flame should die away with minimum residual flame at the jets which in turn should vanish quite quickly. Some burners do this faster than others. If you need to push the valve shut to get rid of the flames then most often the main seal has been damaged or the stem seals are dry and sticking. Its unusual for it to be the return spring but not unheard of in high-houred burners.

If there is a cross-over valve fitted then open it up and open the main blast valve watching for any freezing around the valve that may indicate a leak. These get use very infrequently so subsequently can leak through the stem when operated. You can rely on ‘jumping the flame to ignite the otherside. Freezing on the supply to the crossover valve when its in the off position does not necessarily indicate a leak it is probably just liquid propane trapped under pressure in the pipe causing water vapour to freeze to it.

Now its time for the Whisper valve. Open the appropriate valve and watch the flame checking for any irregularities in the flame pattern or flames escaping from where they shouldn’t. Close the valve and the flame should die away quickly. If a residual flame remains you need to decide whether its propane trapped in the jet assembly, carbon deposits within the jet or the seal in the valve leaking. The easiest way is to wait. It can take up to 30 seconds for the flame to completely die away. Try blowing the residual flame out then crack the main blast valve open and see if it relights. If it does this repeatedly then you’ve got a leak through the valve. If it’s a toggle valve then just like the main valve if pushing it shut cures the problem then it’s a leaking or damaged main seal. Its rarely the return spring but it isn’t unknown. If the valve is adjustable then its most likely…adjustment!

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